Grub2 bug report

[du pingping]

I think that the grub2 needs to work for many grub shell commands.
But critical error is occurred as follow.

Bug scenario is as following.

- at the grub menu, press C key.
- enter "linux /vmlinuz" command to "grub>" shell
- enter above command once more.
- grub2 does not response.

I traced the code lines.
So the grub2 is entered and never ended a loop at the grub_core/lib/relocator.c, free_subchunk function.
And I could not skip this loop, because if i skip this loop, the /proc/cmdline is broken.